In the conventional power tool, an elastomer of a soft resin material is integrally formed with a grip to impart an additional anti-slip function to the grip. However, such an elastomer used in the conventional power tool has a smaller thickness and a higher hardness and therefore has a defect that it may not sufficiently prevent vibration and/or heat from being transferred to a hand.
An elastomer having a larger thickness may be formed by ingenious attempts in the manufacturing technique. However, the elastomer with such a larger thickness has a high repulsion and the use of the elastomer having such a larger thickness leads to increase in size of the grip portion of the power tool. Even if the thickness of the elastomer increased, factors (heat, vibration, etc.) causing an operator's fatigue during a working operation might not be reduced efficiently.
In vie of these problems, there have been developed such kinds of power tools in which a gel-like material was applied to the grip portion to improve vibration insulation and impact absorption as disclosed in the following patent documents 1 and 2.    Patent Document 1: Japanese Patent Provisional Publication No. S61-103786    Patent Document 2: Japanese Patent Provisional Publication No. H7-205055